Temperature Transferability of Force Field Parameters for Dispersion Interactions.

Area of Science:

• Computational chemistry
• Materials science
• Thermodynamics

Background:

• Accurate prediction of material thermodynamic properties relies on precise force fields.
• Atomistic force fields often underestimate dispersion interactions for organic molecules at elevated temperatures.
• This underestimation stems from decreased dielectric constants in bulk liquids as temperature increases.

Purpose of the Study:

• To improve the temperature transferability of atomistic force fields for organic molecules.
• To address the systematic underestimation of intermolecular dispersion interactions at higher temperatures.
• To develop a method for enhancing the accuracy of simulations across wide temperature ranges.

Main Methods:

• Parametrizing dispersion parameters as a linear function of temperature.
• Analyzing underestimates using diatomic molecules to identify contributing factors.
• Testing the enhanced force fields on 66 molecular liquids across four functional groups (alkane, aromatic, ether, ketone-aldehyde).

Main Results:

• Successfully enhanced the temperature transferability of atomistic force fields.
• The developed method accurately predicts properties for a diverse set of molecular liquids.
• Key thermodynamic properties like liquid density, heat of vaporization, heat capacity, and shear viscosity were calculated.

Conclusions:

• Adjusting dispersion parameters linearly with temperature significantly improves force field accuracy.
• This approach provides a more reliable method for simulating organic molecules over broad temperature ranges.
• The findings contribute to more accurate computational predictions in materials science and chemistry.